#include "usart.h"

void USART1_Init(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    // 开启 GPIOA 和 USART1 的时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
    // 配置 PA9 为复用推挽输出（TX）
    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF_PP; // 复用推挽
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    // 配置 PA10 为浮空输入（RX）
    GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; // 浮空输入
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    USART_InitTypeDef USART_InitStructure;
    /* USARTx configured as follow:
          - BaudRate = 115200 baud
          - Word Length = 8 Bits
          - One Stop Bit
          - No parity
          - Hardware flow control disabled (RTS and CTS signals)
          - Receive and transmit enabled
    */
    USART_InitStructure.USART_BaudRate            = 115200;
    USART_InitStructure.USART_WordLength          = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits            = USART_StopBits_1;
    USART_InitStructure.USART_Parity              = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode                = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USART1, &USART_InitStructure);   // 应用配置
    // USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
    USART_Cmd(USART1, ENABLE);                  // 使能 USART1
}

/**
 * @brief  Retargets the C library printf function to the USART.
 * @param  None
 * @retval None
 */
int fputc(int ch, FILE* f) {
    /* Place your implementation of fputc here */
    /* e.g. write a character to the USART */
    USART_SendData(USART1, (uint8_t)ch);

    /* Loop until the end of transmission */
    while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {
    }

    return ch;
}
